olemus
\(n\)-muutuja funktsioonile \(f(x_1, \ldots , x_n)\) ja argumendile \(x_i\in\{x_1, \ldots , x_n\}\) vastav funktsioon
\(\frac{\partial f}{\partial x_i} (x_1, \ldots , x_n) = \lim_{h\rightarrow 0}\limits \frac{f(x_1, \ldots, x_i + h, \ldots , x_n)-f(x_1, \ldots , x_n) }{h}\) ;
sarnaneb tuletisega, kus ülejäänud muutujad peale \(x_i\)
on piirväärtuses konstantsed

Wiktionary:
(mathematics) a derivative with respect to one variable of a function of several variables with the other variables held constant

ülevaateid
https://www.mathsisfun.com/calculus/derivatives-partial.html

https://www.khanacademy.org/math/multivariable-calculus/multivariable-derivatives/partial-derivative-and-gradient-articles/a/introduction-to-partial-derivatives

https://mathworld.wolfram.com/PartialDerivative.html

https://en.wikipedia.org/wiki/Partial_derivative

https://www.plymouth.ac.uk/uploads/production/document/path/3/3736/PlymouthUniversity_MathsandStats_partial_differentiation.pdf

https://www.ma.imperial.ac.uk/~eskelton/partialdiff.pdf